1. Field of the Invention
The present invention relates in general to automatic transmissions of automobiles, and more particularly to an electric cable mounting structure for such automatic transmissions. More specifically, the present invention is concerned with a mounting structure for an electric cable by which respective electric devices mounted in and outside the transmission are electrically connected.
2. Description of the Prior Art
In automatic transmissions for motor vehicles, there is an internal electric device, such as a device including solenoid valves, which is installed in the transmission, an external electric device, such as an electronic controller, which is arranged outside of the transmission, and an electric cable which extends between the internal and external electric devices for transmitting control signals from the external control device to the internal controlled device. The electric cable includes a plurality of wires which are bundled. Usually, the case of the transmission is formed with an opening for inserting the electric cable into the transmission case therethrough. A suitable seal device is fitted to the opening of the transmission for sealing the same.
In order to fix the electric cable to the case of the transmission, various measures have been hitherto proposed and put into practical use. One of these measures is disclosed in Japanese Patent Second Provisional Publication 1-59467, which is shown in FIG. 5 of the accompanying drawings.
In order to clarify the task of the present invention, the conventional measure disclosed by the publication will be described with reference to the drawing in which the cable mounting structure is denoted by numeral 1.
In FIG. 5, denoted by numeral 2 is an aluminium case of an automatic transmission, denoted by numeral 3 is a sleeve for bundling outside electric wires 27, and denoted by numeral 9 is an opening formed in the transmission case 2.
Denoted by numeral 10 is a cylindrical terminal case intimately plugged in the opening 9. Each of the outside wires 27 includes a metal wire covered with a plastic, such as, polyethylene or the like. The outside wires 27 extend to an electronic controller (not shown) located outside of the transmission. The terminal case 10 is constructed of a resilient, oilproof, heat resistant plastic material, such as 6-6 NYLON (trade name) or the like. The terminal case 10 is formed at its inward end with a sleeve portion 11 directed toward the interior of the transmission case 2. The sleeve portion 11 is formed with a plurality of resilient tabs 13 provided by forming a plurality of cuts in the sleeve portion 11. The tabs 13 are resiliently hooked to a shoulder portion (no numeral) formed in the opening 9. The terminal case 10 is formed at its middle portion with an annular flange 12 which is hooked to an outward end of the opening 9 of the case 2. Thus, the terminal case 10 is tightly fixed to the opening 9 due to the work of the tabs 13 and the annular flange 12.
Designated by numeral 14 is an annular groove formed in the terminal case 10. Received in the annular groove 14 is an O-ring 24 for achieving sealing between the transmission case 2 and the terminal case 10. The terminal case 10 is formed at its front end with an annular raised portion 15. Detachably engaged with the annular raised portion 15 is a rubber cover 22. Designated by numeral 16 is a cylindrical space defined in a forward part of the terminal case 10, and denoted by numeral 16a is a cylindrical bore of the terminal case 10 positioned near the sleeve portion 11. Designated by numeral 17 is a cylindrical space defined in a rearward part of the terminal case 10. Intimately installed in the cylindrical bore 16a is a rubber bush 23 which is formed with a plurality of apertures (no numeral) through which electric inside wires 26 extending from the outside wires 27 pass. The inside electric wires 26 extend into the interior of the transmission case 2 and are connected with solenoid valves (not shown) of the internal electric device, each inside wire 26 including a metal wire covered with a heat resistant and oilproof plastic material, such as TEFLON (trade name) or the like. Designated by numeral 25 are press couplers by which the inside wires 26 and the corresponding outside wires 27 are fixedly coupled in one-to-one relationship. The couplers 25 are embedded in an adhesive material 28 packed in the front part of the cylindrical bore 16a of the terminal case 10. Designated by numeral 41 is a naked part of each inside wire 26, while, designated by numeral 42 is a naked part of each inside wire 27.
The above-mentioned cable mounting structure 1 is provided by taking the following assembling steps.
The inside wires 26 which have been connected to the respective solenoid valves in the transmission have their outside ends drawn out through the opening 9 of the transmission case 2 and then the outside ends of the wires 26 are passed through apertures (no numerals) formed in the rubber bush 23 and drawn out therefrom. The plastic cover (viz., the TEFLON sleeve) of the outside end of each inside wire 26 is removed to expose the conducting wire 41. While, the outside wires 27 which have been connected to the electronic controller arranged outside of the transmission have their inside ends passed through a passage (no numeral) of the rubber cover 22 and drawn out from the same. The plastic cover (viz., polyethylene sleeve) of the inside end of each outside wire 27 is removed to expose the conducting wire 42. The exposed ends of the wires 41 and 42 are put in an untreated press coupler 25, and the coupler 25 is pressed to couple the wires 41 and 42. Then, the rubber bush 23 is inserted into the bore 16a of the terminal case 10 from the sleeve portion 11. Thereafter, uncured plastic adhesive 28 is poured into a remaining space in the terminal case 10 in a manner to surround all the couplers 25 and the naked parts of the wires 41 and 42. The adhesive 28 is an electrically insulating, heat resistant and oilproof plastic material, such as epoxy resin, silicone resin or the like. The adhesive 28 is cured to assure fixation of each coupler 25 in the terminal case 10. Then, the rubber cover 22 which has been received on the bundled outside cables 27 is brought into a latching engagement with the annular raised portion 15 of the terminal case 10. Then, the O-ring 14 is put in the annular groove 14 of the terminal case 10, and the terminal case 10 is inserted into the opening 9 of the transmission case 2. When the terminal case 10 is sufficiently inserted into the opening 9, the resilient tabs 13 of the case 10 are spreaded radially outward and latchingly engaged with the shoulder portion of the opening 9 of the transmission case 2. With these steps, the cable mounting structure 1 is provided and the terminal case 10 is tightly connected to the opening 9 assuring sealing therebetween.
However, due to its construction, the above-mentioned conventional cable mounting structure has the following inherent drawbacks.
First, the manual coupling of the two wires 26 and 27 with the coupler 25 is difficult, which reduces the labor effectiveness in producing the transmission.
Second, due to the awkward task of coupling the inside and outside wires 26 and 27, a so-called mis-coupling between the two wires tends to occur.